Ashutosh Sharma, who plays for Railways, is the latest batter to join the elite list.
Asutosh hit an 11-ball half-century vs Arunachal Pradesh in the Syed Mushtaq Ali Trophy.
Before Ashutosh, Yuvraj Singh held the record for fastest 50 by an Indian.
Yuvraj Singh also held the overall record for 16 years.
That record was broken by Nepal's Dipendra Singh Airee last month.
Dipendra struck a 9-ball fifty against Mongolia at Asian Games.
Yuvraj took 12 balls to reach his half-century against England in the 2007 T20 World Cup.
Yuvraj whacked six sixes in an over off Stuart Broad.
Chris Gayle and Afghanistan's Hazratullah Zazai are next.
Three batters, including Indian youngster Yashasvi Jaiswal, have notched fifties off 13 balls.
KL Rahul, Pat Cummins and Andre Russel have 15-ball half-centuries.